Piston-ring



C. K. HILL.

PISTON RING.

APPLICATION FILED DEC.8, I919.

' Patented Nov. 23, 1920-.

cnmns K. HI/LL, or CLEVELAND, OHIO,

PATENT" car es.

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RING COMPANY, 013 BOSTON, MASSACHUSETTS, 1 A CORPORATION OF MASSA- cHsE'rrs.

PISTON-RING. I

- Application filed December 8, 1919. Serial No. 343,161.

= To all abhom'tt may concern:

Be it known that I CHARLES K. HILL, a

' citizen-of the United tates,-and resident of Cleveland, in the countyof Cuyahoga and State of Ohio, have invented new and useful Improvementsin Piston-Rings,of which the following is a specification.

nevertheless, such as to be broadl This invention relates'to pistonpackings particularly adapted for use with lnternal combustion engines.-While especially suited for use in such engines the inventlonfisl,

use u v all engines operating by means 0 gaseous or fluidressure'against a piston. v

Ane cient piston packmg'for internal combustion engines must admit of acom aratively large variation in the clearance etween the piston andcylinder. These engines operate under a relatively high temperature, andalthough the cyllnder is cooled either by air blast or water circulaton, the 7 piston is not so cooled. This necessitates a rather lar eclearance between. the piston and cylinder when the engine is cool 111order that vthere ma be no binding when the engine is warme up.

The ordinary method of packing at present in use consists in spl t ringssprung into grooves, the rings being normally of greater diameter thanthe internal diameter of the cylinder. The resiliency of the ring isrelied upon to keep it in contact with the I inner wall of the cylinder.Q however, does not when compressed or exbecome distorted, causingunequal bearing,

Such a ring,

panded retain its circular shape, but tends to I j the loss ofcompression andunequal wear on the cylinder.

I am aware that it has been heretofore proposed to form the packing oftwo rings,

an outer-packing ring normally the same slze as the internal diameter ofthe cylinder and a one piece, split, spring, follower ring inside thepacking ring to force it into contact with the cylinder. I am also awarethat it has been proposed to have the spring followerring bear againstboth a beveled edge of the packing ring and the flat side of the groovein the piston, in order to force the bearing ring both radially againstthe cylinder and axially against the other side of the groove and thusto prevent leakage between the packing ring and both the cylindeg andthe side of the groove. This condoes not Wholly obviate the unequalexpan- SlOllOf the split ring.

It is an object of the present invention to retain all the advantagesaccruing from havlng the packing made of a plurality of parts andfurther to eliminate or minimize SlIStOIftlOII of the packing. The outerpackmg ring is uniformly pressed outward against the cylinder throughoutits circumfere'nce sand there'is consequently no loss of pressure and nounequal wear onthe cylinder. v .1 have illustrated an embodiment of myinvention in several different forms in the accompanying drawings, inwhich- F1gure l is a cross sectional view partly in 1 perspectiveshowing a portion of the piston and cylinder together with the ringconstruction y Fig. 2 is a plan view, partly in cross section, on theline 2-2 ,of Fig. 1, on a slightly reduced scale;

Fig. 3 is a fragmentary view of a portion of one of the followerelements together with its spring;

Fig. 4 is a view similar to Fig. 3 but of a modified form; j 1

F'g. 5 is a bottom view of partof one of the followersv shown in Fig.4:;

Fig. 6' is a fragmentary View similar.

Patented Nov. 23, 1920..

Fig. '2" is also a fragmentary view similar I to Fig. 2. but showing adifferent modification of the spring structure.

In the several figures of the drawing, 8 designates the cylinder wall,and 9 the piston having thev groove 10 cut therein. In this groove isthe split bearing or contact ring 11, having the beveled lower surface12 and being split at 11. Bearing against this beveled surface 12 is theupper beveled surface 13 of the sectional follower ring The followerring 14: isvcomposed of a plurality of similar sections 15, six suchsections being shown in Fig. 2.

In the form shown in Fig. 2, each section 15 is pressed outward by aseparate fiat steel spring 16. The springs 16 bear against the bottom ofthe groove in the piston at their center points 17 and their ends fitinto slots 18 in the sections 15, which slots are substantiallyequidistant from the centers of the sections.

The ends of adjacent sections 15 are fitted one to another byoverlapping joints 19. While this particular type of joint is notessential it ishighly desirable that a por-, tion of the contact of thejoint be on a line substantially concentric with, the circumference ofthe piston or tangent to such a line. This preserves connection betweenthe several sections when the follower is expanded and thus aids insecuring continuity and uniformity of pressure.

In the form shown in Fig. 3,,the slots 18- are shown extending fullyfrom top to bottom of the sections 15. This form is preferable from amanufacturing standpoint, and the spring 16 may be kept from riding outof the slot by a punch prick above it.

In Fig. 4 the slot is shown at 18' in an alternative form extending onlypartly up the member 15. Fig.5 showsthis form of slot as seen frombelow.

' While Fi 2 shows the springs as straight, it is not to be understoodthat this indicates that this is their normal position and that they arenot then exerting any outward pres sure on the follower elements. Theirnormal position when unstressed may be either flat, concave, or slightlyconvex considered in relation to the piston. In the structure I shown inFig. 2, they would-normally be concave, and hence when straight as shownin the figure they would be exerting an outwardpressure due to theirtendency to resume their normalconcave condition.

The modificationi'shown in Fig. 6 shows I a convex spring- 16 with smallreversed curves at each end. This results in one convex surface bearingagainst QaChFI'SQCiZIOII 15 and two such SillfaCSFbEMiIlg a ainst thebase of the groove on the piston. Thls struc ture eliminates the.slo't18'or 185 the eleg ment 15.

The modification shown in discloses the use of a continuous sinuousspring 16" in; stead of the separate springs 16 or 16. As' shown, thespring bears against-each section 15 at two pointsbut it is obvious,that this.v

may be varied by increasing'or decreasing the number of convolutions inthe spring.

The form of sectional follower ring, each section of which isindividually pressed outp predetermined point.

in the form shown, also against the wall of the groove.

In former devices which had the combined radial and endwise thrust, butwith an intes,

glfal follower ring, a warping of either the;

bearing ring or follower ring would cause an unequal bearing against theside of the l groove with consequent loss of pressure.

'In the present device the sectional follower ring cannot warp,--and onaccount of the inherent flexibility of its sectional'str'uq' ture itwill tend to take up any warping of the bearing ring and cause uniformcontact with the side of the groove. "1"

I claim;-

In combination, a piston havlng a rectangular annular groove therein,and a packing in said groove'comprising 'a continuous re sihent packingring divided at a single point, the ring having concentric inner andouter surfaces, one lateral surface perpendicular thereto andadapted tocontact with a lateral wall of the groove, and the other lateral surfacebeing oblique and forming an acute angle with the outer surface, asectionalfollower ring formed of sections having 'co'n centric outer andinner surfaces, one lateral surface being oblique and adaptedto contactwith the oblique surface of the packing ring andthe other lateralsurface ada ted.

tc contact with the opposite lateral wa l of thegroove, a spring oflesswidth than the follower member bearing against each fol--.

follower in a radial direction, a slot passing part way across eachfollower at the bearing pointsv and adapted to receive the sprin 1 lowersection, and adapted to expand the ends and to retain them between theslot en and the side of the groove to prevent lateral play and maintainthe spring thrust at the. Signed by me at Cleveland, Ohio,'this29th dayof November, 1919. j

' I CHAS. K. HILL. I

